If everyone knew everything, I'd argue that we'd have moral absolutes for the simple fact that we'd innately know the consequences of our actions and inactions and thus be able to adequately differentiate the harmless, from the harmful and the better path from the worst path.

The thing is, if you can't refute this then what I call excavative morality might be something you'd believe in. A "Moral excavationist" (I coined this term), is someone who believes that morality can rightfully be set in stone with absolutes however we are likely to figure out moral absolutes as quickly as we forget them and the number of words required to describe even a single moral absolute might be a bit overwhelming and have an equally overwhelming number of varient versions. In some cases though something is always immoral such as child rape while also not requiring much description to identify it as wrong. Through life experience, the expulsion of ignorances and arrogances we may very well find some moral guidelines that we could rightfully call moral absolutes, however these moral absolutes will likely remain concealed from the sight of others.